Various mobile computing devices (“mobile devices”) automatically rotate information they display, e.g., when the mobile devices detect that the user may be viewing the display in a rotated orientation. As examples, the APPLE® IPHONE® and IPAD® mobile devices rotate displayed information automatically when the user rotates the mobile device. Other examples of mobile computing devices with rotation functions are digital cameras, “smartphones,” tablet computers, etc. When a user rotates the mobile device from a vertical or “portrait” orientation to a horizontal or “landscape” orientation, the computing device automatically rotates the displayed information so that the information remains in the same orientation it was in before the user rotated the mobile device. As an example, if the displayed information included the text “ABC123” in a normal reading orientation (see FIG. 1A) before the user rotated the computing device, and then the user rotated the display device by approximately 90 degrees, the mobile device can rotate the text by 90 degrees so that the displayed text remains in the normal reading orientation. (See FIG. 1C.)
Mobile devices employ one or more sensors to detect orientation with respect to a plane (e.g., earth's surface) or force of gravity and rotate the information so that the “top” of the displayed information is farther from the plane than the “bottom” of the information. Examples of sensors that mobile devices employ to detect their tilt angle are accelerometers and gyroscopic sensors.
This automatic rotation function is useful when the user views the display while standing, sitting, or lying in a prone position (i.e., face down). When the user is lying in a supine position (i.e., face up), however, the rotation function is sometimes dysfunctional. When a user is in the supine position, the computing device can rotate the displayed information at undesirable times. To prevent this behavior, some computing devices include a switch (see, e.g., switch 104 in FIG. 1A) to disable the rotation function.